Penobscot County Sheriff Glenn Ross speaks at a news conference Tuesday in Bangor, Maine, where it was announced that Kyle Dube, of Orono, was charged with murder in the death of Nichole Cable, who was last seen May 12. (ASSOCIATED PRESS / David Sharp)

BANGOR, Maine (AP) — When 15-year-old Nichole Cable left home May 12, she told her family she was heading out to see someone she'd met on Facebook.

The high school sophomore never came back.

Now, a 20-year-old man faces charges in her death after a body believed to be the missing teen's was found in a wooded area north of Bangor.

Kyle Dube, of Orono, was charged with murder Tuesday, a day after the remains were found in Old Town, Maine State Police Lt. Christopher Coleman said at a news conference.

Police declined to reveal the circumstances of her death, describe her relationship with Dube or discuss the evidence they have against him. Nor was it clear whether her Facebook relationship had anything to do with her disappearance and homicide.

More details were expected to emerge once police submit an affidavit of probable cause, which could happen as early as Wednesday, when Dube is due to make his first court appearance in the case.

Dube was already in jail serving a sentence for fleeing police on a motorcycle at more than 100 mph, according to state police. Stephen McCausland, a state police spokesman, said investigators believe Dube is "solely responsible for her death."

Tyler-Ann Harris, 16, who described herself as Nichole's best friend, said Tuesday that Dube and Nichole had met a couple of months earlier and planned to see each other the weekend she vanished, before he had to report to jail.

Harris, who attended Old Town High School with Nichole, said she had never met Dube and wasn't sure of his relationship with her friend. But she said Nichole didn't fear him.

"She was really happy even though she went through a lot of hard stuff in her life. She always knew how to see the bright side of things," Harris said, dabbing her eyes with a tissue. "She didn't always get along with people, and she had an attitude. But that's a teenage girl. And she was just happy all the time."

Dube's parents live in a tidy brick and white-sided house in Orono. A young man who answered the door said the family didn't want to talk and closed the door firmly in a reporter's face.

Dube's attorney, Stephen Smith, did not immediately return a call for comment.

Dube had worked for The Getchell Agency, an organization that cares for people with disabilities in Bangor, since June until he quit last week. The agency's CEO, Rena Getchell, said in an email to The Associated Press that his background check and employee reviews were satisfactory.

"He gave us no reason to believe that he might be capable of this crime," she said. "This is devastating news to us as we truly are a family."

The body believed to be Nichole's was found about 9:30 p.m. Monday by a warden who was searching the woods with a dog, officials said. The medical examiner took possession to make a positive identification and issue a ruling on how she died.

Nichole's mother, Kristine Wiley, said after she disappeared that Nichole had said she was going out to meet someone she knew from Facebook. But Wiley said she didn't know the identity of the person.

Dozens of law enforcement officers, using aircraft and dogs, and hundreds of civilian volunteers spent days searching for the teen, who lived in Glenburn.

"This initially started as a missing person's case and sadly it's transitioned to a homicide investigation," said Penobscot County Sheriff Glenn Ross.

He urged parents to keep an eye on their children's online activities.

"This reminds us that parents should have oversight of Internet activities of their children. They should monitor what's going on and then use normal precautions that we all know, as far as how much information we provide," Ross said.

Cable's stepfather, Jason Wiley, said Tuesday that he and Kristine Wiley were still processing Tuesday's news and would take reporters' questions on Wednesday.